Water has become increasingly recognized as an important natural resource of limited availability in some geographical areas making conservation measures desirable.
The conventional water closet includes a water storage tank, a waste receipt bowl and passageways for creating siphoning or jet action by the rapid release of water from the water storage tank. Traditionally such water closets have been designed to empty the entire contents of the water tank each time the flushing actuator is operated. However, it is now known that less than the entire water contents of the tank is needed to adequately purge the waste receiving bowl of liquid wastes and refill it with clean water. Usually, however, the entire water content of the tank is needed for removal of solid wastes.
A large variety of devices have been suggested for conserving water in the flushing operation. Some, such as the device illustrated in my earlier U.S. Pat. No. 4,145,774, have two selectable modes of operation. In one mode a flush is initiated which utilizes all of the water in the tank. In the other mode a flush is initiated which uses only part of the stored water. Other types of devices have only one mode of operation in which less than the entire tank volume is utilized.
One popular type of discharge valve closure is the type shown in U.S. Pat. No. 4,028,748. It has a unitary molded body forming the sealing portion, which sealingly engages the valve seat of the discharge valve, and a buoyancy chamber which extends downwardly and has a drain hole at the bottom. When such a conventional discharge valve closure is in the closed position, water drains from the buoyancy chamber. When the valve is lifted by operation of the actuating arm, it is buoyant and remains raised with the valve open until the water level lowers below the discharge valve thereupon permitting the discharge valve to fall by gravity back into the closed position upon the valve seat.
Similar operation is obtained by the valves shown in U.S. Pat. No. 2,741,775 and 2,598,967. These devices have no buoyancy chamber but instead rely upon a lightweight foam material for buoyancy.
Other inventors discovered that the conventional discharge closure of the type having a buoyancy chamber can be made to close prematurely, that is before the water level falls below the level of the discharge valve closure, by providing a small bleeder port in the buoyancy chamber above or below the sealing portion of the discharge valve closure. In some, with the bleeder port above the seal, a snorkel extends upwardly above the water surface level of the filled tank.
In those with a bleeder hole below the seal, preferably the bleeder hole is formed so that it will be facing upwardly when the discharge valve closure is raised to its full open position.
These structures permit the escape of air from the buoyancy chamber so that water may enter the chamber and reduce the buoyancy of the closure to the point that the valve will fall closed before the entire tank contents has been exhausted through the discharge valve. Such structures are shown in U.S. Pat. Nos. 3,935,598; 3,969,775; 4,000,526; and 4,189,795. A check valve is used to control the discharge valve closure disclosed in U.S. Pat. Nos. 3,733,618 and 3,935,598.
Some devices permit no adjustment for controllably varying the rate of water inlet into the buoyancy chamber which rate determines the rate of change of the buoyancy of the closure and therefore determines the water level at which the discharge valve will fall closed. One device provides a float arrangement attached to the valve for adjustment purposes. Still others provide adjustment by a variety of structures for varying the drain hole size by a type of a manually adjustable valve means. Others change the drain hole size by providing a plurality of interchangeable inserts having orifices of different sizes. Ordinarily the size of the bottom drain hole is adjusted in the prior art units.
U.S. Pat. No. 3,324,482 discloses an adjustment valve mechanism with a threaded screw in the bottom wall of the valve closure for controlling the flow rate of water entering the buoyancy chamber through the drain hole. This valve is not intended to be closed completely because that would prevent drainage of the buoyancy chamber when the valve closure reseats at the end of the flush cycle and therefore it would not operate. In U.S. Pat. No. 4,189,795 a variety of other mechanisms for adjusting the drain hole size are disclosed including a bottom wall containing a threaded, adjusting screw and a drain opening that is mated with a vertically movable sleeve adjustment.
My prior U.S. Pat. No. 4,145,774 utilized a buoyancy chamber with a bleeder hole system but combined it with a unique bistable handle to give improved modes of operation.
It is desirable that an adjustment be provided for the discharge valve closures having a bleeder port in order to permit the adjustable selection of the water level at which the discharge valve closure will prematurely close. Such adjustment is desirable to compensate for variations in the tank structures of different toilet manufacturers, to compensate for the different needs of different sewage and water systems and to permit the owner to select the water volume which the owner desires to utilize when obtaining a reduced water volume flush.
However, the adjustment systems which have previously been suggested are difficult to adjust especially for people of limited dexterity or mechanical ability and are subject to the deposit of minerals and other materials which interfere with their operation. Additionally, it is not only more difficult for the owner but more expensive for the manufacturer to provide a plurality of interchangeable drain hole inserts or other additional parts for an adjustable orifice. Finally, drain holes which are adjustable in size are more sensitive to the effect of deposition of materials such as particles or mineral deposits which will further constrict the size of the orifice.
Water closets with very small tanks will sometimes flush improperly with a valve closure using a bleeder hole system. It is therefore desirable to provide a replacement closure that also permits the bleeder to be turned completely OFF. Such an embodiment, to be functional, requires that the air bleed be shut off in a way that will not impede the closures ability to properly drain after reseating on the valve seat at the end of a flush cycle so it will be buoyant. Such an embodiment must not permit the build up of sedimentation in the bottom of the buoyancy chamber.
There is, therefore, a need for a discharge valve closure which can be adjusted for selection of the desired water level at which the valve will close and yet which is simple, inexpensive and easy to manufacture and does not require interchangeable parts.
Previous dual flush devices have worked more efficiently when a reduced flush was done after a full flush cycle because the bowl is filled to its maximum water level at the end of a full flush. Conventional ballcocks (or filler valves) are presently made in various designs which direct a minor portion of incoming water into the overflow tube from which it flows into the bowl and a major portion of the incoming water directly into the tank. They are engineered to refill the bowl in the time it takes to refill the tank after having been drained completely from a conventional full flush cycle.
However, after a partial or limited flush, not as much time is needed to refill the tank because less water was used and therefore less water is directed into the bowl. Consequently in small fixtures the bowl, after a short flush, has insufficient water to initiate the strong siphon or draining action which is desired to remove all the bowl contents after each flush.
One system for assuring that the bowl will be completely filled after either type of flush would be to merely permit a greater rate of water flow through the overflow pipe into the bowl by making the minor water outlet orifice larger. Although this would cause the bowl to always be filled by filling it quicker, after the bowl has been filled following a full flush and while the tank is still filling, excess water will be directed into the bowl and drain out into the sewer. This reduces the water savings from a dual flush system.
There is therefore a need for an apparatus which can easily be retrofit to dual flush water closets and which causes the bowl to be filled to its maximum desirable height after both types of flushes without wasting water after either.